On November 20, 1993, at 1300 hours Pacific standard time, an experimental Yakovlev Yak-55M, N7090L, collided with the terrain while attempting a forced landing at Metz airport, Greenfield, California. The pilot was conducting a local visual flight rules aerobatic flight. The airplane, registered to John W. Heinrich, Concord, California, and operated by the pilot, sustained substantial damage. The certificated private pilot, the sole occupant, was not injured. Visual meteorological conditions prevailed. The flight originated at Metz airport at an undetermined time. The pilot contacted the Federal Aviation Administration on November 24, 1993. At that time, he reported that he was performing aerobatic maneuvers when he experienced engine problems. The pilot executed a forced landing to Metz airport, but the airplane's altitude was insufficient to make the runway. The pilot removed the airplane from the accident site without informing the National Transportation Safety Board. Neither the pilot nor the operator provided the Safety Board with the required Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1/2.